| dc.description.abstract | Understanding particle dynamics and their characteristics is essential to the operation, design, and optimization of chemical looping reactors. The chemical looping dry reforming (CLDR) process is a novel hydrogen production process in which methane and carbon dioxide mixture is converted into syngas in a cyclic oxidation-reduction reaction in the presence of an oxygen carrier. This paper presents a three-dimensional computational fluid dynamic model to study the fluid flow pattern in a chemical looping dry reforming methane (CLDRM) reactor. The numerical analysis was applied through Eulerian and Lagrangian approaches. This multiphase model design comprises a dual circulating fluidized bed consisting of a high-velocity air reactor (AR) with a high-velocity riser, a cyclone chamber (CC), a fluidizing bed fuel reactor (FR), and a connecting loop, which closes the loop between AR and FR. Analysis of gas-solid hydrodynamics in CLDRM was performed to understand the particles distribution, volume fraction, flow pattern, velocity and circulation between the AR and FR. The evolution of particle flow circulation rate was carefully analyzed to understand the particle material rebalance and the transfer of solid particles between reactors operating on different velocities. The results showed that the CLDR system experiences a pressure imbalance between the reduction and oxidation zones, which causes solid particles to undergo a highly intricate and turbulent pulse flow. This results in periodic bursts of pulses that lead to the intermittent transportation of particles ― in the form of particle clusters― from high-pressure areas to regions with lower pressure. This paper discusses the impacts of velocity and geometric modifications on the distribution of the particles. The results showed that the fluidized beds exhibited a periodic pulse pattern with various phenomena occurring in a millisecond, and it was concluded that an air velocity of 3.2 m/sec, fuel mass flow rate of 0.0025 kg/sec, and connection loop diameter of 25 mm were ideal operating parameters. | en_US |
